Activating Stake Fee

A guide to the activating stake fee under SAM, including how it is calculated and how validators can manage participation.

Activating Stake Fee

The activating stake fee is a one-time charge on new stake delegated to a validator through the SAM auction. It is sized by how far the validator's bid sits above the auction clearing rate. The fee funds the re-delegation that brings that new stake in, which lets Marinade move more stake to high bidders and improves staker APY.

Why this exists

Stakers trust Marinade to allocate their stake to the validators that deliver the most value. All Marinade staking products that use SAM rely on this. SAM achieves this through an auction, where validators bid for stake. Stake then needs to be re-delegated from lower-bidding validators to higher-bidding ones as bids change. Re-delegation has a real cost: stake spends one epoch unproductive while it deactivates and reactivates, which reduces staker APY.

Without a way to fund that cost, Marinade can only re-delegate when the bid revenue from the destination validator at least partially offsets the activation hit. In a slower bid environment, this means less re-delegation and longer waits for validators to receive meaningful stake from SAM.

The activating stake fee unlocks this bottleneck. Validators who win new stake pay a fee that helps Marinade cover the cost of the re-delegation that brought it in. The fee revenue funds further re-delegation, which lets Marinade move more stake to high bidders. Validators get faster access to stake when they bid for it, and stakers get higher APY because their stake reaches better validators sooner.

How payments work

Validators continue to pay the existing per-epoch payment on their active SAM stake. This is the auction bid payment described in the SAM overview. The activating stake fee is paid on top of this, on activating stake only.

Activating stake means stake that Marinade just delegated to the validator.

The full payment for an epoch is:

payment = auctionEffectiveBidPmpe × activeStake / 1000  
        + max(0, bidPmpe - auctionEffectiveBidPmpe) × activatingStake / 1000

The new term is the activating fee. The size of the fee comes from the overbid: the gap between a validator's bidPmpe and the auction's auctionEffectiveBidPmpe. A larger overbid means a larger fee on each unit of activating stake.

Each unit of new stake is charged exactly once. It appears as activating in one epoch's snapshot, then transitions to active in the next.

Worked examples

Two validators with the same auction rank pay the same activating fee, regardless of commission. A higher commission raises both bidPmpe and auctionEffectiveBidPmpe by the same amount, so the overbid that drives the fee stays constant.

Example 1: scaling with the overbid

Both validators have 100,000 SOL of activating stake.

	Validator A	Validator B
bidPmpe	0.420	0.480
auctionEffectiveBidPmpe	0.387	0.387
Overbid	0.033	0.093
Activating fee	3.3 SOL	9.3 SOL

The fee scales linearly with the overbid. A larger gap above the clearing rate means a larger fee on each unit of activating stake.

Example 2: scaling with activating stake

Both validators have the same overbid of 0.033.

	Validator C	Validator D
Activating stake	100,000 SOL	250,000 SOL
Activating fee	3.3 SOL	8.25 SOL

The fee scales linearly with the amount of activating stake received in the epoch.

Example 3: same rank, different commissions

Two validators with the same auction rank but different commission structures.

	Validator E	Validator F
bidPmpe	0.420	0.450
auctionEffectiveBidPmpe	0.387	0.417
Overbid	0.033	0.033
Activating stake	100,000 SOL	100,000 SOL
Activating fee	3.3 SOL	3.3 SOL

Both validators pay the same fee because their overbid is identical. Commission structure does not create unfairness in the activating fee.

Managing your participation

The activating fee can recur. As long as a validator is bidding above clearing and has room under their maxStakeWanted cap, Marinade may continue allocating new stake to them in subsequent epochs. Each new allocation triggers its own activating fee.

Validators have two levers to manage how much new stake they receive, and therefore how much they pay.

• Lower maxStakeWanted: Setting maxStakeWanted at or below current active stake means no new stake will be allocated, regardless of the bid. Existing active stake stays delegated. This is the cleanest way to stop receiving new allocations without affecting bid history.

• Lower bidPmpe: Reducing the bid lowers the overbid and the fee per unit of activating stake. It also lowers the validator's auction rank, which in most cases means losing the rank required to win new stake at all. Validators typically need to be first in the rank order to win stake, so a lower bid often results in no allocation rather than a smaller fee. Lowering bidPmpe from one epoch to the next can also trigger the Bid Reduction Penalty (bidTooLowPenalty). Adjusting maxStakeWanted is almost always the better lever.

When changes take effect

Changes to maxStakeWanted and bidPmpe take effect in the next auction. Validators should set new values before the end of the current epoch so they are picked up.

Previewing activating stake

The PSR dashboard shows an estimation of incoming delegation for the current epoch before the snapshot locks. Validators can use it to anticipate the fee before it settles.

Related mechanisms

The activating stake fee and the Bond Risk Reduction Mechanism both reference auctionEffectiveBidPmpe and can apply in the same epoch, but they cover different situations. The activating stake fee charges validators on new stake won through the auction. The Bond Risk Reduction Mechanism applies when a validator's bond is below the minimum required for their existing active stake.

For the governance context behind this change, see MIP-19 on the Marinade Forum.